| 摘要 |
PURPOSE:To obtain the mode converting element of less insertion losses with a simple constitution by parallel providing an optical guide whose line width increases with a mild gradient then sharply dereases in the mid-region of the optical guide line. CONSTITUTION:A line 2 which is the dielectric of the refractive index higher than those of ambient space, ambient medium S2, S3 and whose line width expands with a mild gradient from one end part and decreases at a sharp gradient on the other end part is parallel provided by way of the intermediate layer S0 of the specified distance R to one side of the region on the way of the optical guide line 1 which is the dielectric of the refractive index higher than those of ambient space, ambient medium S1, S2. The light energy such as of TE1 mode or the like incident from the incident end of this line 1 enters the line 2 on the way, where it is mode changed and again it returns into the line 1 in the state of the converted mode, from where it emits. This simple constitution lets mode changing be accomplished with low insertion losses without making phase adjustment between modes. If electrodes are provided along both sides of the line 2 and voltage is applied thereto, the mode changing is not accomplished. |
